Lithographic plate and the process for producing the same.



C. CHISHOL LITHOGRAPHIC PLATE AND TH OCESS UCING THE SAME.

APPLICATIO ED NOV. 9,1

1,149,974, Patented Aug. 10, 1915.

MZIIEEEBS v [in/5177171 Hi5 2177f.

CLIFTON CHISHOLM, OF SAN FRANCISCO, CALIFORNIA.

LITHOGRAPHIC PLATE AND THE PROCESS FOR PRODUCING THE SAME.

Specification of Letters Patent.

Patented Aug. to, 1915.

Application filed November 9, 1914. Serial N 0. 871,427.

To all whom it may concern Be it known that I, CLIFTON CHIsHoLM, acitizen of the United States, residing in the city and county of SanFrancisco and State of California, have invented a new and usefulImprovement in Lithographic Plates and the Process for Producing theSame, of which the following is a specification.

My invention relates to lithographic printing plates and the process forproducing the same wherein a highly flexible and resilient base isprovided with an extremely hard granular metallic surface; and theobjects of my invention are, first, to provide an improved lithographicplate having a hard flexible granular printing surface with a resilientelastic base or backing, said base being adapted to absorb the shock ofa type bar and prevent the indentation of the hard printing surface;second, to provide an improved lithographic plate that may be cheaplyproduced; third, to provide an improved plate that is-highly flexible sothat the same may be easily rolled around a typewriter or similar platenof small diameter; and fourth, to provide an improved plate of thecharacter described having an extremely hard flexible granular surfaceadapted to readily retain moisture and ink such as is used in connectionwith the offset lithographic process.

I accomplished these several features by means of the process and platehereinafter described, reference being had to the drawings forming'apart of the present specificat-ion wherein like characters of referenceused to designate similar parts throughout the said specification anddrawings, and in which Figure l is a plan view of a lithographic plateconstructed in accordance with my process, a portion of the hardmetallic surface being broken away in order to disclose the cathodethereon which is in turn partly broken away in order to disclose theresilient elastic base; and Figs. 2, 3 and 4 are greatly enlargedsectional views of the plate disclosing various stages of the processhereinafter more fully set forth. I

In order to provide an improved lithographic plate of extremeflexibility and resiliency having a hard granular surface thereon asheet of comparatively thin celluloid plate A is painted with a suitablevolatile solvent, such as acetone or the like,

mixed with a very finely powdered metal B,

rates the said particles become fixed therein so that a greatlymagnified section of the plate A would appear as illustrated in Fig. 2of the drawings. After a suitable cathode is thus secured to the surfaceof the plateA a further plating of copper is electrolytically depositedthereon, as disclosed in Fig. 3 of the drawings, for the purpose ofincreasing the conductivityof the cathode thus formed in order that aplating of aliarder and more porous metal G, preferably nickel, may beelectrolytically deposited thereon, as disclosed in Fig. 4 of thedrawings, such electrolytical deposition constituting the next step ofthe process,"and also for the purpose of presenting a smooth surface,the purpose of which will be hereinafter more fully set forth. Theelectrolytical deposition of the nickel is to provide a hard, thin,non-oxidizing, absorbent surface C of a thickness suitable forlithographic purposes but not thick enough to destroy the physicalproperties of -the celluloid base. The granular surface is provided forthe purpose of ell'cctively retaining such moisture and ink as is neededfor the lithographic printing process and may be produced eitherchemically or mechanically.

A lithographic printing plate produced by the above described processwill possess extreme flexibility and resiliency as well as extremehardness of surface, which characteristics are essential for good sharpreproductions. The flexibility and resiliency of the celluloid base willtend to prolong the life of the, hard granular printing surface and atthe same time will provide an elastic base which will readily supportthe thin layer of electrolytically deposited nickel C, which will yieldreadily and not strain or crack the thin nickel layer C when the plateis bent or rolled around a platen of small diameter. The resiliency ofthe celluloid base A also provides an elastic cushion ar- For shortruns, 'where a small number of copies are to be produced, an eflicientplate, suitable for the purpose, may beprovided by omitting the final ornickel plating and the printing done directly from the smooth coppersurface. I have found also from actual experiment that for. light workwhere a small number of copies are to be produced, an efficient platesuitable for the purpose may be provided by omitting theelectrolytically disposed second layer of copper.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is- 1 1. A lithographic plate comprisingafiexible resilient base; a layer of powdered copper embedded in thesurface of the base; and a layer of thin hard metal imposed upon thelayer of copper. v

2. A lithographic plate comprising a flexible resilient base; a layer ofpowdered copper embedded in the surface of the base; and

a thin layer of nickel imposed upon th layer of copper. 3. Alithographic plate comprising a flexible resilient celluloid base; alayer of pow dered copper embedded in the surface of the base; and athin layer of hard metal imposed upon the layer of copper.

4, A lithographic plate comprising aflex ible resilient celluloid base;a layer of powdered copper embedded in the surface of the celluloidbase; and a thin layer of nickel imposed upon the layer of copper.

5. A lithographic plate comprising a flexible resilient celluloid base;a thin layer of powdered copper embedded in the surface of the celluloidbase; an electrolytically depos-' -ited second layer of copper imposedupon the'layei' of powdered copper; and a thin layer of hard metalimposed upon the electrolytically deposited layer of copper.

6. A lithographic plate comprising a flexible resilient celluloid base;a thin layer of powdered copper embedded in the surface of the celluloidbase; an electrolytically def posited second layer of copper on thefirst mentioned layer; and a thin layer of nickel electrolyticallydeposited upon the second mentioned layer of copper.

7. A lithographic plate comprising a resilient flexible celluloid base';a thin layer of powdered copper embedded in the surface of the celluloidbase; a second layer of electrolytically deposited copper upon the firstmentioned layer; and a thin granular layer of hard metal deposited uponthe second mentioned layer.

8. A lithographic plate comprising a resilient flexible celluloid base;a thin layerof the celluloid base a second layerof electrotioned layer.

9. The step in the process of producing lithographic plates whichconsists in partially dissolving the surface'of a thin celluloid plate,applying to such partially dissolved surface a thin layer of powderedcopper. I

10. The process of producing lithographic plates which consists inpartially dissolving the surface ofa thin celluloid plate, applying tosuch partially dissolved surface a thin layer of powderedmetal, andelectroof nickel deposited upon the second menlytically depositing onthe powdered metal a thin layer of hard metal.

11. The process of producing lithographic plates which consists in patially dissolving the surface of a thin celluloid plate, applying tosuch partially dissolved surface a thin layer of powdered copper, andelectrolyti- 'cally depositing onthe powdered cop-pera thin layer ofhard metal. 1

12. The process of producing lithographic plates which consists inpartially dissolving .the surface of a thin resilient, fl 'Xible plate,

applying to such partially disso ved surface a thin layer of powderedmetal in order to form a cathode, and electrolytically depositing on thecathode a thin layer of hard metal.

. 13. The process of producing lithographic plates which consists inpartially dissolving the surface of a thin resilient flexible plate,applying to such partially 'dissolved surface a thin layer of powderedcopper in order to form a cathode, and electrolytically deposit-.

ing on the cathode a thin granular layer of hard metal.

14. The process of producing lithographic plates which consists inpartially dissolving the surface of a thin celluloid plate, applying tosuch partially dissolved surface a thin layer of powdered copper inorder to forma cathode, electrolytically depositing asecond thin layerof copper on the cathode, and electrolytically depositing a thin layerof hard metal on the electrolytically deposited copper.

15. The process of producing lithographic plates which consists inpartially dissolving the surface of a thin celluloid plate, applying tosuch partially dissolved surface a thin layer of owdered copper in orderto form a catho e, electrolytically depositing on the powdered copper asecond thin layer of copper, and electrolytically depositing a thingranular layer of'hard metal on the electrolytically deposited copper.

16. The process of producing lithographic v plates which consists inpartially dissolving the surface of a tliin celluloid plate, applying tosuch partially dissolved surface a thin layer of powdered copper so asto form a cathode, electrolytically depositing on the powdered copper asecond thin layer of copper, and electrolytically depositing on thesecond layer of copper a thin granular layer of nickel.

17. The process of producing lithographic plateswhich consists inpartially dissolving the surface of a thin celluloid plate with asolvent having particles of powdered copper suspended therein so as toform a cathode, and electrolytically depositing on the cathode a thinlayer of hard metal.

18. The process of producing lithographic plates which consists inpartially dissolving the surface of a thin celluloid plate with avolatile solvent having particles of powdered copper suspended thereinso as to embed the said particles within the surface of thus the platewhen the solvent evaporates,

on the cathode a thln granular layer of nickel.

In witness whereof I hereunto set my signature in the presence of twosubscribing 5 witnesses.

' CLIFTUN CHISHOLM. Witnesses:

IRENE Downer, CHAS. F. DUISENBERG.

